Fossil Find: Scientists Uncover New T-Rex Relative Hidden in a Mongolian Museum

In an exciting twist of paleontological fate, scientists have uncovered a new ancestor of the Tyrannosaurus rex, buried among misidentified fossils for over five decades! This heartwarming story blends adventure, persistence, and excitement as researchers piece together the intriguing family tree of these remarkable creatures.

New T-Rex ancestor discovered in drawers of Mongolian institute — This handout artist’s illustration shows the newly discovered dinosaur species Khankhuuluu mongoliensis, a significant find that updates what we know about the T-Rex family lineage.

Imagine this: bones that were thought to be from a different dinosaur species, Alectrosaurus, have been sitting quietly in storage for half a century! Initially discovered in southeastern Mongolia in the early 1970s, these fossils had been overlooked until Jared Voris, a passionate Ph.D. student, took a closer look during a research trip. His keen eye recognized that these bones were something entirely new.

Fast forward to today, and thanks to Voris’s rediscovery, we welcome Khankhuuluu mongoliensis into the dino family—nicknamed the “dragon prince of Mongolia.” At about 13 feet long and weighing around 750 pounds, this ancestor of the iconic T-Rex was much smaller and more slender, resembling a very large horse.

The dragon prince of Mongolia — An artistic representation of Khankhuuluu mongoliensis, which tells a new story in the evolution of tyrannosaurs.

Darla Zelenitsky, a co-author of the discovery from the University of Calgary, expressed excitement about how this find helps clarify the complex family history of tyrannosaurs. Previously, it had been a tangled web. This new species reveals a migrating route from Asia to North America where tyrannosaurs evolved, leading to the well-known T-Rex.

Interestingly, it’s believed that Khankhuuluu or its relatives journeyed across the ancient land bridge connecting Siberia and Alaska, paving the way for their evolution in North America. Over time, as these great dinosaurs spread, they adapted into several distinct forms, one of which was the T-Rex. However, it was not without its challenges—an asteroid hit Earth around 66 million years ago, leading to a massive extinction that forever changed life on our planet.

As scientists continue to uncover the layers of Earth’s history, it’s clear that breathtaking discoveries like Khankhuuluu mongoliensis remind us of the remarkable tales waiting to be told in the fossilized remains of our prehistoric past.

For more details:
Jared T. Voris et al, A new Mongolian tyrannosauroid and the evolution of Eutyrannosauria, Nature (2025). DOI: 10.1038/s41586-025-08964-6.

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